Considerations for the Management of Gram-Positive Pathogens in the Intensive Care Unit

摘要

Surveillance data demonstrate that the majority of gram-positive bacterial isolates obtained in the intensive care unit (ICU) setting are staphylococci and enterococci. Staphylo-cocci, mainly Staphylococcus aureus and coagulase-negative staphylococci, compose the majority of clinical isolates. Data from 25 North American ICUs reported methicillin-resistant S aureus (MRSA)in more than 50% of the S aureus organisms isolated mainly from a respiratory source. In addition to MRSA, S aureus with reduced susceptibility to vancomycin has been reported. Enterococci are typically considered opportunistic pathogens, infecting immunocompromised hosts. Resistance of enterococci to vancomycin, along with the newer gram-positive antimicrobials, is an increasing problem. Investigators have demonstrated that nearly 30% of enterococci isolated in the ICU are resistant to vancomycin. The high level of resistance and limited therapeutic options make treating resistant gram-positive organisms such as MRSA and vancomycin-resistant enterococci particularly problematic. While vancomycin has long been considered the gold standard for the treatment of resistant gram-positive infections, newer agents (eg, quinupristin-dalfopristin, linezolid, and daptomycin) offer therapeutic alternatives.